#include <iostream>

using namespace std;

const int N = 110;

int r, c;
int a[N][N];
int f[N][N]; // 备忘录

int dx[] = {0, 0, 1, -1};
int dy[] = {1, -1, 0, 0};

int dfs(int i, int j)
{
	if(f[i][j]) return f[i][j];

	int len = 1;
	//上下左右四个方向搜
	for(int k = 0; k < 4; k++)
	{
		int x = i + dx[k], y = j + dy[k];
		if(x < 1 || x > r || y < 1 || y > c) continue; // 剪枝
		if(a[x][y] >= a[i][j]) continue;

		len = max(len, dfs(x, y) + 1);
	}

	return f[i][j] = len;
}

int main()
{
	cin >> r >> c;
	for(int i = 1; i <= r; i++)
	{
		for(int j = 1; j <= c; j++)
		{
			cin >> a[i][j];
		}
	}

	int ret = 1;
	for(int i = 1; i <= r; i++)
	{
		for(int j = 1; j <= c; j++)
		{
			ret = max(ret, dfs(i, j));
		}
	}
	cout << ret << endl;

	return 0;
}